Our new Solar Panel Installation

[Azrich]

Rich are you going to get shade from the tree you may have to sneek over at night and cut it down :lol:

Why did they use 25 angle that is more for winter, mine has a 20 angle more for summer. It will generate more power in the summer at 20 angle which is when the rate is most costly. Did they ask you how you wanted it or just install the system?

The tree in the photo is really not a problem. It is farther away than it looks and casts no shadow on the roof. However, after we had our installation designed in June, our next door neighbor planted a tree that could be a problem. He travels a lot so I might take your advice when he goes away sometime. Would a couple of gallons of bleach take care of it, do you think? :evil:

We could have requested a 20 degree angle, but I trusted our installers suggestion of 25 degrees. They have installed hundreds of systems in Tucson and just finished a $550,000 installation at the Nature Conservancy headquarters.

Very nice looking install! The did a great job attaching the mounts to the roof.

25* mounting angle will be a good compromise between summer/winter production.

Thanks, drees. We were really pleased with the installer's "fit and finish" of their rack system, conduit, and inverter installation in the garage. They even painted all the conduit in the garage to match the Santa Fe Gold wall!

In a dusty place like here, dust buildup on solar panels does make for a significant reduction of power. But they're very easy to clean, and you don't need to get on the roof either - just spray them with a garden hose!

Regarding the red cover for the inverter, you could call SMA (916-625-0870) and ask for a replacement cover for the Sunnyboy 6000US. Failing that, red paint is readily available :lol:

They told us to hose them off in the morning when it was cool, not during the heat of a summer day. We have a lot of minerals in our water here, so I would probably squeegee them dry. This won't happen very often, but our roof is easy to get to and to walk on.

Thanks, everyone, for the great comments and advice. To our surprise, Tucson Electric Power came this morning to install the solar meter and they also switched our Time of Use meter to one that works with a solar system. When the system was turned on, the meter immediately began going backwards! Wow, what a great feeling - decreasing our dependence on fossil fuels! Thanks, again.

 

[DaveEV]

We could have requested a 20 degree angle, but I trusted our installers suggestion of 25 degrees.

You can run the PVwatts numbers for your location, but it looks like 25* will get you slightly more than 20* year round. You give up a tiny bit of power May-Aug bit it's not significant.

They told us to hose them off in the morning when it was cool, not during the heat of a summer day. We have a lot of minerals in our water here, so I would probably squeegee them dry. This won't happen very often, but our roof is easy to get to and to walk on.

You might just try using a cotton towel and/or car duster (think mop on a nice handle) and a small spray bottle to hit any sticky bits. I found that most of the dust that accumulates on my panels easily wipes off without using any water at all. 15 min of wiping and and you're done. A bit more elbow grease than hitting it with the hose but then you don't need to worry about water spots if you have hard water.

 

[Azrich]

So far, so good.

Our newly installed 5.8 kW photovoltaic system has been operating for 3 full days now. The weather in Tucson has been 100% sunny with temperatures in the mid 80's during the afternoon. Our system's inverter comes on at about 7:20 am and shuts off at 5:30 pm.

Our kWh production has been 34 or 33 kWh each of the three days. This is better than we expected. If it did this for 30 days, the system would produce 990 kWh in a month. This is more than our average use for 8 months out of the year.

Hope it can keep this up.

Our data monitoring system will be operating any day now.

 

[planet4ever]

You might just try using a cotton towel and/or car duster (think mop on a nice handle) and a small spray bottle to hit any sticky bits.

You mean like a mop on a nice looooooooooooooooong handle?

 

[JasonT]

Our kWh production has been 34 or 33 kWh each of the three days. This is better than we expected. If it did this for 30 days, the system would produce 990 kWh in a month. This is more than our average use for 8 months out of the year.

My 5.25 system produced 31x2 and 30 kWh the past three days. To give you an idea of what you're going to get, I averaged 27.6 kWh/day in October, and my average since August of 2009 is 27.2. I can't give you a calendar year total, but August 2, 2009 -> August 1, 2010 total is 9973, or monthly average of 831kWh. I would imagine you'll get closer to 920kWh, but that still rocks

Edit: I had the wrong numbers, totally rewrote post

 

[Boomer23]

Wow, you guys get great insolation in AZ.

Here in Calif, my 5.16 kW system facing slightly west of south produced only 23, 23 and 21 kWh for the last three sunny days. That's typical of my system for early November over the last 3 years. Total production high for a year was 8,466 kWh. I have to check my records for roof angle. We didn't have a choice, since the panels were mounted on a pitched roof.

Great to hear that you're doing so well!

 

[DaveEV]

You might just try using a cotton towel and/or car duster (think mop on a nice handle) and a small spray bottle to hit any sticky bits.

You mean like a mop on a nice looooooooooooooooong handle?

Yeah, that's not going to work. Going to need a really long handle! How dirty do the panels get with them on that type of slope? I'd expect rain to do a decent enough job to not have to worry about it unless you live in an area with a lot of dust.

 

[planet4ever]

How dirty do the panels get with them on that type of slope? I'd expect rain to do a decent enough job to not have to worry about it unless you live in an area with a lot of dust.

We've had the panels for four years, and so far just counted on rain. I don't like climbing on roofs these days, but I've considered asking one of my grandsons to get up above the panels with a hose and nozzle. It hasn't happened because their mother doesn't much like the idea.

So far the production is holding up pretty well on our 7kW system. Yesterday was hazy, and we still got 23kWh out of it. We average about 45 kWh/day when it peaks in June.

 

[mwalsh]

Weather permitting, our PV install kicks off tomorrow morning!

 

[Gonewild]

I use a car wash sprayer attachment. I put in Blue Coral car wash NOT the wash and wax type I has a softener agent to be more spot free. I have used plan water and man big time water spot as AZrich said our water is hard here. I did use a wide driveway broom because I can walk all the way around the panels.

 

[Gonewild]

Here rain is not good enough to wash the panel alone. We can go close to 6 month without a drop of rain. And we do get lots of dust or call it dirt from being so dry. I have had dirt storms I will call them where you can almost sweep are vacuum it up.

 

[Coffee_Slurry]

I haven't cleaned my panels, ever. They're very hard to get to, so I just have to trust the rain to do it.

It would cost about $200 to have someone come clean them, so I'm keeping an eye on the annual production, and will pay for cleaning when I'm losing about $50/yr in power. I'm a long way off from that yet, even with a bunch of ash that is probably up there from the wildfires in 2007.

(Also: Sunniest November ever!)

 

[ERG4ALL]

We had our PV system installed this spring and started generating electricity on June 2nd. We live in the mountains of AZ (about 6,800 ft.) where it is cool and a very intense sun. Our system was advertised to produce 6,460 Watts in direct sunlight. On a clear day depending on the inclination of the sun it produces a peak of 6,760 Watts. What I enjoyed about the engineering of the system is that the installing company uses Enphase microinverters. The 34 panels are 235W Sharp panels with 14.4% efficiency and each one of them has its own 190W inverter. The advantage is that you can add panels in the future like tinker-toys without having to buy a second inverter or a larger one than you need initially. The other nice feature is that by using panels with slightly more generation capacity than the inverters is that the total output on a sunny day is a bell curve with a flat top. What this means is that the panels come up to full capacity of the inverters sooner than they would if the panels were only 190W. Thus, the total power produced (i.e. the area under the curve) is greater. Good to see that many LEAF buyers like myself are planning on using PV to "Drive on Sunshine". If you like you can see the output of our system at “https:// enlighten.enphaseenergy.com/public/systems/ xpWw4801”.

 

[Boomer23]

Weather permitting, our PV install kicks off tomorrow morning!

Exciting, Michael! We'll have a lot to talk about on Saturday morning if you make it to the gathering.

 

[Boomer23]

I use a car wash sprayer attachment. I put in Blue Coral car wash NOT the wash and wax type I has a softener agent to be more spot free. I have used plan water and man big time water spot as AZrich said our water is hard here. I did use a wide driveway broom because I can walk all the way around the panels.

My panels are on top of a second story tile roof with no place to walk around them. I tried shooting hose water up there, but I doubt that it did much. I realized that you have to actually brush the panels lightly to dislodge the dirt, just like washing a car. It's not enough to just spray the panels.

I finally got the longest freaking handled brush I could find at Home Depot. It has a 15.5 foot aluminum handle and a soft window washing brush. I stand on a ladder on top of a patio roof and reach up with the long brush and a hose. I'm able to reach all 24 panels that way, and it works great. I don't love doing it, so I'm glad that it's only really needed once or twice a year.

 

[Azrich]

Weather permitting, our PV install kicks off tomorrow morning!

Congrats, Michael. Let me know when you are up and generating. We'll have to compare my 215 watt SunPower panels to your 230 watt panels on a sunny day. Our installers said SunPower is discontinuing the 215's in December. That might be why they changed you to the 230's. Ours were assembled in Mexico. They look very nice with black frames.

Keep in touch.

 

[Coffee_Slurry]

The other nice feature is that by using panels with slightly more generation capacity than the inverters is that the total output on a sunny day is a bell curve with a flat top. What this means is that the panels come up to full capacity of the inverters sooner than they would if the panels were only 190W. Thus, the total power produced (i.e. the area under the curve) is greater.

You might want to rethink that. The area under the curve truncated by the "flat top" more than makes up for the slight inverter inefficiencies at low light. Inverters quickly get to peak efficiency (96%?), and the low-light range where you see inefficiency is just producing a trickle anyway.

If your inverters are underrated, and regularly saturating, I don't see how that translates to Win.

My inverter is slightly undersized just for cost reasons. It didn't make sense to step up to the next power, since it rarely saturates. But cost aside, I'd rather have the bigger inverter for those bright days in May.

 

[ERG4ALL]

If your inverters are underrated, and regularly saturating, I don't see how that translates to Win.

The area under the top of the curve is less than the area under both of the slopes of the bell curves. You can prove this for yourself by taking a piece of graph paper and setting the "x" axis to time from, say 7AM to 5PM and the "y" axis to Watts. On the "x" axis place a mark at 7AM, 10:40AM, noon, 1:20PM and 5PM. On the "y" axis place a mark up at 190W and another at 235W. Draw a line from zero watts at 7AM to 190W at noon. Then another from noon back down to zero watts at 5PM. This represents the 190W panels output (for ease of demonstration you don't have to bother making all of these curved lines as they appear on my website). Then draw a line from zero watts to 190 watts at 10:40AM (this is from real world monitoring - the 235W panels reach 190W of output at 10:40). Next, continue the line up to 235W at noon. Then continue with the down slope hitting 190W at 1:20PM and from there on down to zero watts at 5PM. This is the output of the 235W panels. Finally, draw a line that represents the inverter max. output. This is a line from 190W at 10:40AM to 190W at 1:20PM. If you have used graph paper it is easy to see that just one leg of the additional power (the area under the curves) generated by the 235W panels over the 190W panels more than makes up for the amount that is limited by the inverters (the top triangle). And as you said it is a question of total output versus cost of inverters.

I wish I could say that I was smart enough to come up with this by myself, but the credit goes to the electrical engineers at Enphase. You can read the technical paper at: http://www.enphaseenergy.com/downloads/Enphase_White_Paper_Module_Rightsizing.pdf

My only point is for those of you that plan on using PV to charge the LEAF might want to keep this in mind when working with a solar company.

 

[mwalsh]

Install under way:

 

[Gonewild]

1 picture of the truck is all you could post? Add more at the end of the day. :mrgreen: